Evaluate the following integral using trigonometric substitution.

${\displaystyle \underset{\phantom{}}{\overset{\phantom{}}{}}}\frac{dt}{t^2\sqrt[\phantom{2}]{64-t^2}}$

${\displaystyle \underset{\phantom{}}{\overset{\phantom{}}{}}}\frac{dt}{t^2\sqrt[\phantom{2}]{64-t^2}}=$

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